Electrical receptacle



Patented Apr. 11, 1939 UNITED STATES PATENT OFFICE' Philip E. Hamilton, Beaver Falls, Pa.

Application November 14, 1936, Serial No. 110,934

2 Claims.

This invention relates to electrical xtures, and more particularly has reference to outlet receptacles such as are adapted to receive the jacks of attachment plugs.

It is well known that the standard outlet receptacles which are now in use have undesirable features. One of the most important of these features is that these receptacles have been dangerous because they will permit the insertion of various metallic objects, such as hairpins, screw drivers or the like, and numerous persons have received very severe shocks as a result thereof.

Moreover, the slots in the receptacles become dlled or clogged with foreign matter, and thus render proper contact diiiicult and present the possibility of short circuitlng.

While `many attempts have been made to pro- .vide outlet receptacles with a high safety factor, these devices either have been totally ineffective or else so expensive as to render the use of the same prohibitive.

An important object 'of my invention is to provide an outlet receptacle with a high factor of safety. y

Another object of my invention is to provide a receptacle which will prevent possible electrical shock to persons using the same.

Yet another object of my invention is to provide an outlet box which is simple and economical in construction 'and which will require only slight changes from the present conventional type of receptacle.

Yet another object of my invention 'is to provide a receptacle which will prevent the entrance of dirt and other foreign matter'to the slots.

With these and other objects in view, which may be incident to my improvements, the invention consists in the parts and combinations to be hereinafter set forth and claimed, with the understanding that the several necessary elements comprising my invention may be varied in construction, proportions and arrangement, without departing from the spirit and scope of the appended claims.

In order to make my invention more clearly understood, I have shown in the accompanying drawing means for carrying the same into practical effect without limiting thev improvements `in their useful applications tothe particular con"- structions, which, for the purpose of explanation. y .f

have been made the subject of illustration.

Figure 2 is a view taken along the lines 2-2 of Figure 1.

Figure 3 is a view taken along the lines 3--3 of Figure 2.

Figure 4 is a view taken along the lines 4-4 of a Figure 2.

Figure 5 is a view taken along the lines 5--5 of Figure l.

Figure 6 isa view taken along the lines 6 6 of Figure 1.

Figure '7 is a detail view showing the clip for holding the yoke member to the-0utlet box.

Figure 8 is a View similar to Figure 2, showing a modified form of my device.

Referring to the drawing, and more particu- 1B larlyjto Figure 2, I have shown a conventional outlet box l, having ears 2 provided with screw threaded apertures 2', the purpose of which will later become apparent. The outlet box is adapted to be positioned in the usual manner in a recess in the wall, or in any other desired location.

The receptacle for the attachment plug comprises a base 3 of insulating material, such asA vulcanized rubber or thelike. The top face of the base is cut away as at 4, lforming a centrally disposed raised portion 5. The sides of the base are also cut away as shown at '5'. Channels 6 and 1, which are diametrically opposed, extend through the base member, as shown in Figure 5.

While I have shown a. receptacle having two 30.

outlets, it is of course to be understood that this is 'merely for the purpose of illustration and that a more or less number of outlets may be employed if desired. Inasmuch as both of these outlets are of identical construction, I shall confine my description to but one, for the purpose of simplicity.

The channels 6 and 1 are adapted to receive the jacks of an attachment plug (not shown), and there are positioned in the channels resil- 40 ient contact elements 8 and 9. The resilient contacts are engaged by the jacks when the plug is inoperative position.

The resilient contacts 8 and 9 are connected tovbinding posts lll, which are positioned in the l5k cutaway portion 5', by means 4of metallic conductors depicted generally at Il. Inasmuch as the conductors il are of conventional form, it is not necessary to go into detail in regard to these elements.

As shown in Figure 3, the raised portion 5 of the base is provided with laterally extending lugs l2 positioned between the binding posts. It will be/appreciated that these members will prevent any possibility of short-circuiting.

`plate I3. As shown in Figure 2, the upturned ends I of the bracket I4 are provided with tongues I6. The tongues I6 are pressed out of the bracket. The base is' cut away as shown at I'I so as to permit the tongue I6 to t over the end of the insulating lplate and hold such plate.

firmly in position. It is obvious that this will prevent any movement of the plate relative to the base and the supporting bracket. 'I'he bracket terminates in flanged portions I8 which are provided with apertures I 9.

The ends of the bracket I4 iit within channels provided in the side of the base 3. These channels prevent any tendency toward relative rotation between the bracket and the base.

The base 3v is also provided with a centrally disposed bore 2| which has a countersunk portion 22 in the raised portion 5. An internally threaded metallic sleeve 23 having a hexagonal head 24 is fitted into the bore 2|.

The bracket I4 and the plate I3 are provided with centrally aligned openings 25 and 28 through generally 35.

which extend a screw 21 which is screwed into the metallic sleeve for holding the base 3, the insulating plate I3, and the bracket I4, together.

A circular disc or shutterZB is adapted to Iit over each of the outlets of the base 3. Diametrically opposed slots 29 and 30 extend through the disc. A centrally arranged aperture 3l 4is provided in the lower face of the disc 28. A similar aperture 32 extending at right angles to the aperture 3I is provided in the upper face of the base. A helical spring 33 is removably positioned in kthese apertures. One of the looped ends 34 of the spring extends into the aperture 3I and the other looped end -of the spring 34 extends into the aperture 32. While I have shown the apertures 3l and 32 as being placed at right angles to each other, it is within the scope of my invention to form these apertures in any desired manner, the purposeof the apertures being to afford a means of resiliently mounting the disc on the. base. It

will be readilyappreciated that this spring resiliently opposes any rotation of the disc with respect to the base.

'I'hebase 3 and the disc 28 are so assembled that the slots 29 and 3U are 90 degrees `out of alignment with the channels 6 and 1. 'I'he spring 33, while of course opposing rotation of the disc, does permit rotation of the disc in either direction until the slots 29 and 30 register with the channels 6 and 'I. 'I'he strength of the spring 33 may be varied, but it is vpreferably suiliciently strong for the disc 28 to resist rotation except by the jacks of an attachment plug, and in any event the spring. is strong enough to return the disc to the positionl where the slots are out of register with the channels 6 and 'I.

In order to hold the disc in proper position with respectto the base 3, I employ a plate designated The plate 35 is of the split type and is formed of t`wo sections 36 and 31. As best shown in Figure 4, the plate is dividedvcentrally at its ends, but is divided orf-center in the middle due to the fact that the metallic sleeve 23 extends through the central portion of the base.

Referring now to Figure 4, it can be seen that the disc 28 is provided with a peripheral groove 38 -into which the plate 35 is adapted to fit. The

groove is of such depth as to permit the disc to rotate, but it will not allow any excess vertical or horizontal movement. It will be appreciated that the use of apertures in thev disc and base for positioning the spring is particularly emcacious, as it obviates the securingof the spring to either the disc or base. With this arrangement, the spring can be readily inserted or removed in a minimum of time. The relative heights of the raised central portion 5 of the base 3 and the screwed into the aperture 2 in the ear 2 on theY outlet box.

A standard cover plate 44 of suitable insulating material, such as hard rubber, having apertures 45l which correspond to the shape of the discs, is secured to the base 3 by means of a screw 46 which is screwed into the upper end of the me tallic sleeve 23.

`The loperation of my device is believed to be apparent from the foregoing description. The

slots 29 and 3B of the disc 28 are normally out of alignment with the channels E and 'I in the base, and the jacks of an attachment plug are rst inserted into the slots 29 and 30; the attachment plug is then rotated in either direction until the slots come into register with the channels 6 and 1, and the plug is then further inserted until it abuts the upper face of the disc. In this position the jacks are in engagement with the contacts 8 and 9, and close the circuit. It should be noted that the jacks of the plug are securely -held in operative position, not only by resiliency of the contact elements, but by the action on the jacks, which is caused by the discs and the spring.

When it is desired to disconnect the plug, it is Withdrawn from the base, whereupon the disc 28 returns to its inoperative position, in which the slots 29 and 30 are out `of alignment with channels 6 and`1.

In Figure 8 I have shown a somewhat modified form of my device.' In this form, instead of employing a metallic sleeve which extends tthrough the base 3, the plate 35 is provided with a central portion having downturned edges 4'I provided with screw threads which are in comthe munication with a recess 48, formed in the base 3. The cover plate is secured to the receptacle by merely screwing the screw 45 into the opening 46. In this form it is not necessary to secure the base to the bracket by means of a screw which extends through the bracket and into the base.

It will be appreciated that my invention provides an electrical outlet box which will prevent any accidental or careless contact with the electrical contact elements in the receptacle. By the employment'of the rotatable discs, access to the contacts within the base can be had only by Furthermore, the outlet box c'an be manufactured quite cheaply, and only slight changes are `necessary in order to convert the conventional or standard type of outlet box intoV an embodiment of my invention.

WhileA I have shown and-,described the .prei'erred embodiment of my invention, I wish it to be understood that I do not coniine myself to the precise details of construction herein set forth, by Way of illustration, as it is apparent that many changes and variations may be made therein, by those skilled in the art, without departing from the spirit of the invention, or exceeding the scope of the appended claims. I claim: l. An electrical receptacle comprising abody portion, channels in the body portion, an electrical contact member in each channel, a discslotted aperture in the lower portion voli the shutter member, a slotted aperture in the upper portion of the body portion, a helical spring having its ends bent over along its diameter, said spring being positioned with said bent-over portions in said apertures to normally hold the shutter slots out of register with the channels.

2. An electrical receptacle comprising a body portion', a pair of channels extending therethrough, an electrical contact member in each channel, a disc-like shutter member having a pair of slots adapted to register with the channels, said shutter'member having a peripheral groove,

a plate attached to the body portion and fitting into said peripheral groove and preventing movement of the shutter away from said body portion, said plate being split4 substantially in the middle into two plate strips, projections on each plate strip, clips for engaging said projections and holding the plate strips together, a slotted aperture centrally disposed in the upper portion of the body portion, a slotted aperture centrally disposed in the bottom portion of the shutter member, a helical spring having its ends bent over along its diameter, said spring being4 positioned with said bent-over portions in said apertures to normally hold the shutter slots out of register with the channels.

PHILIP El HAMMIJI'ON." 30 

